Clutch including a pump

Abstract

A clutch comprising a pump is disclosed. The pump is operatively connected to the clutch such that a clutch slip event will cause the pump to delivery fluid from a fluid source to a region surrounding the friction plates of the clutch. The operation of the pump manages heat that is generated by the dynamic friction of the slipping clutch plates. The pump and associated fluid delivery methods are removably securable to an upstream end of an input shaft of the clutch. This allows the pump and associated fluid delivery methods to be used as modular components, that are easy to remove and replace for maintenance purposes, it also allows easier access to the internals of the clutch for maintenance.

The invention claimed is: 
     
       1. A clutch for driving a winch, the clutch comprising: an input shaft for connection to a motor and being operatively connected to at least one input friction plate for rotation therewith; an output shaft for driving a winch, the output shaft being coaxial with and having at least a portion radially within the input shaft, and being operatively connected to at least one output friction plate for rotation therewith, wherein the at least one input friction plate and the at least one output friction plate are in contact with each other so that torque can be transferred from the input shaft to the output shaft via the input and output friction plates; and a pump comprising: an inlet for connection to a fluid source; an outlet in fluid communication with the input and output friction plates; an outer rotor operatively connected to the input shaft for rotation therewith; and an inner rotor having at least a portion radially within the outer rotor, the inner rotor being operatively connected to the output shaft for rotation therewith, wherein differential rotation of the input shaft and the output shaft causes the pump to pump fluid to the input and output friction plates, wherein the input shaft includes a first end located adjacent the at least one input friction plate and an opposed, open second end, wherein the pump has at least a portion radially within the input shaft and the pump is accessible and removable via the second end; wherein the input shaft includes a first end located adjacent the at least one input friction plate and an opposed, open second end, wherein the pump has at least a portion radially within the input shaft and the pump is accessible and removable via the second end; and wherein the open second end having a seal ring surrounding the open second end. 
     
     
       2. The clutch of  claim 1 , wherein the outer rotor is arranged to rotate about a first axis and the inner rotor is arranged to rotate about a second axis that is not aligned with the first axis. 
     
     
       3. The clutch of  claim 1 , wherein the pump is a positive displacement pump. 
     
     
       4. The clutch of  claim 3 , wherein the pump is a gerotor pump. 
     
     
       5. The clutch of  claim 1 , wherein the output shaft comprises an outer shaft and an inner shaft disposed coaxially with and having at least a portion radially within the outer shaft, wherein the inner shaft is operatively connected to the outer shaft for rotation therewith. 
     
     
       6. The clutch of  claim 5 , wherein the inner shaft further comprises:
 a central bore in fluid communication with the outlet of the pump; and 
 first fluid delivery channels in fluid communication with the input and output friction plates. 
 
     
     
       7. The clutch of  claim 6 , wherein the outer shaft includes second fluid delivery channels therethrough in fluid communication with the first fluid delivery channels of the inner shaft and the input and output friction plates. 
     
     
       8. The clutch of  claim 5 , wherein:
 the pump further comprises an outlet plate operatively connected to the inner rotor such that the inner rotor rotates therewith, wherein the outlet plate further comprises one or more first protrusions extending therefrom; and 
 the inner shaft includes one or more first recesses at a connection end thereof, and the one or more first protrusions engage with the one or more first recesses to operatively connect the inner rotor to the inner shaft. 
 
     
     
       9. The clutch of  claim 1 , wherein the outer rotor comprises one or more second recesses on an outer surface thereof, an inner surface of the input shaft includes one or more second protrusions extending therefrom, and the one or more second protrusions engage the one or more second recesses to operatively connect the outer rotor to the input shaft. 
     
     
       10. The clutch of  claim 1 , wherein the pump further comprises an inlet seal, wherein the inlet seal seals the pump radially within the input shaft. 
     
     
       11. The clutch of  claim 5 , wherein the inner shaft is removably secured to the outer shaft. 
     
     
       12. A method for removing heat from the clutch of  claim 1 , the method comprising the step of delivering fluid from a fluid source to the input and output friction plates during a clutch slip event. 
     
     
       13. The method of  claim 12 , wherein a clutch slip event provides differential rotation of the inner rotor and the outer rotor of the pump to deliver fluid from the fluid source to the input and output friction plates. 
     
     
       14. A method of assembling a clutch, wherein the clutch comprises: an input shaft for connection to a motor, the input shaft having a first end located adjacent at least one input friction plate for rotation therewith and an opposed, open second end; the open second end having a seal ring surrounding the open second end; an output shaft for driving a winch, the output shaft being coaxial with and having at least a portion radially within the input shaft, and being operatively connected to at least one output friction plate for rotation therewith, wherein the at least one input friction plate and the at least one output friction plate are in contact with each other so that torque can be transferred from the input shaft to the output shaft via the input and output friction plates; and the method comprising the step of removably securing a pump through the open second end of the input shaft, wherein the pump comprises: an inlet for connection to a fluid source; an outlet in fluid communication with the input and output friction plates; an outer rotor operatively connected to the input shaft for rotation therewith; and an inner rotor having at least a portion radially within the outer rotor, the inner rotor being operatively connected to the output shaft for rotation therewith. 
     
     
       15. The method of  claim 14 , wherein the step of removably securing the pump includes using an inlet seal to seal the pump radially within the input shaft. 
     
     
       16. The method of  claim 14 , wherein the output shaft comprises an outer shaft and an inner shaft and the method further comprises the step of removably securing the inner shaft coaxially with and at least partially within the outer shaft for rotation therewith, prior to the step of removably securing the pump. 
     
     
       17. The method of  claim 16 , wherein the inner shaft and pump are removably engaged with each other.